Abstract: A method of etching a film of a substrate is provided. The substrate includes an underlying region, the film and a mask. The film is provided on the underlying region. The mask is provided on the film. The method comprises performing main etching on the film. The main etching is plasma etching of the film and exposes at least a part of the underlying region. The method further comprises forming a protective layer on at least a side wall surface of the mask after the performing of the main etching. A material of the protective layer is different from a material of the film. The method further comprises performing over-etching on the film after the forming of the protective layer. The over-etching is plasma etching of the film.

Abstract: This invention provides an insulating protective material effective for protection of electronic and electric devices such as electronics elements. This insulating protective material contains at least one hydrous oxide of a metal which has ion exchange properties together with a fusion bonding component such as low-melting glass, epoxy resin, phenolic resin, silicone resin, etc. and a filler such as fused silica, .beta.-eucryptite, glass fiber, glass beads, etc.Said specific hydrous oxide can be used together with a sulfur-containing organic high molecular weight compound.The hydrous oxides used in protective materials as a sealing material for electronic and electric devices can capture an ionic impurity eluted from the components of the protective material and fix it therein thereby to provide stable electronic materials excellent in performance.

Abstract: There is provided a magnetic recording material produced by coating on a support a magnetic coating composition which contains as main components a magnetic powder and a binder, the binder comprising an urethane acrylate synthesized using a polyester polyol having a particular structure, and by irradiating the resulting magnetic coat with electron beams to harden it. The polyester polyol contains polyhydric alcohol component, 50 mole % or more of which is a dihydric alcohol selected from the class (A) described below, and/or polybasic acid component, 50 mole % or more of which is a dibasic acid selected from the class (B) described below. The urethane acrylate is synthesized under such a condition that it may have two or more of (meth)acryloyl groups per molecule. Thus, improvements in electromagnetic properties and in durability are attained.

Abstract: A magnetic recording medium is described, comprising a support and a magnetic layer disposed thereon, said magnetic layer containing as its binder component a combination of at least one member of each of the following groups of compounds (1) to (3) that has been exposed to electron beams:(1) vinyl chloride type resin, vinyl acetate type resin, vinyl chloride-vinyl acetate type resin, each containing from 5.times.10.sup.-5 to 2.times.10.sup.-3 equivalents of --CO.sub.2 H groups per gram of copolymer, and nitrocellulose resin;(2) urethane resins and urethane-acrylate oligomers; and(3) compounds containing an isocyanurate ring and at least two groups selected from acryloyl and methacryloyl groups.

Abstract: Certain new derivatives of 2,6,7-trioxabicyclo[2,2,2]octane are found to undergo cationic ring-opening polymerization with positive expansion in volume or with no substantial change in volume, in contrast with known polymerizable compounds such as epoxides which present considerable shrinkage in volume on polymerization. These new bicyclic orthoester compounds can be prepared in a facile way known per se.

Abstract: A precoated steel sheet and a process for production thereof is provided which comprises coating a resin composition comprising mainly an acryloxyloxy- or methacryloyloxy-terminated polyester on the surface of a steel sheet, said acryloyloxy- or methacryloyloxy-terminated polyester being prepared by reacting a hydroxy-terminated polyester comprising (a) a dicarboxylic acid unit containing about 10 to about 80 mol % of a terephthalic acid unit and (b) dihydric alcohol unit containing about 30 mol % or more of a dihydric alcohol unit containing 3 or more carbon atoms, and having a number average molecular weight of about 400 to about 5,000, with acrylic acid or methacrylic acid, and curing the thus-coated resin composition by irradiating the sheet with an electron beam.

Abstract: A curable composition comprising:(A) at least one spiro-orthoester compound having at least one spiro-orthoester group represented by the formula: [I] ##STR1## wherein n is an integer of 3-5, (B) at least one curing agent selected from the group consisting of organic polybasic acids and their anhydrides,(C) optionally, an epoxy compound having at least one epoxy group, and(D) optionally a cationic polymerization catalyst when the composition comprises ingredient (C).Said composition is small in shrinkage on curing, and provides a cured product of high dimensional accuracy when used as a molding material.

Abstract: A curable urethane material which shows no change in volume on polymerization and curing is prepared from polyisocyanate compound, polyhydroxy compound and a new compound 1-alkyl-4-hydroxymethyl-2,6,7-trioxabicyclo[2,2,2]octane.

Abstract: Novel 2-methylene-1,4,6-trioxaspiro[4,6]undecane has both cationic polymerizability and radical ring-opening polymerizability, and it can be produced by reacting a 2-halomethyl-1,4,6-trioxaspiro[4,6]undecane with an alkali to effect dehydrohalogenation.

Abstract: A process for production of an acryloyloxy- or methacryloyloxy-terminated polyester is described, which comprises reacting a specific hydroxy-terminated polyester with acrylic acid or methacrylic acid, wherein the hydroxy-terminated polyester comprises (a) a dicarboxylic acid unit comprising about 10 to about 80 mol % of a terephthalic acid unit and about 90 to about 20 mol % of another dicarboxylic acid unit and (b) a dihydric alcohol unit containing about 30 mol % or more of a dihydric alcohol unit containing 3 or more carbon atoms and having a number average molecular weight of about 400 to about 5,000.

Abstract: An emulsion of a crosslinking type comprises an oligoester-(meth)acrylate having at least two (meth)acryloyl groups in a molecule, a molecular weight of not more than 1000 per one (meth)acryloyl group, and a boiling point at a normal pressure of at least 200.degree. C and a polymer emulsion of an oil-in-water type.

Abstract: Process for curing an oligoacrylate containing 3-6 acryloyl groups and at least one cyclohexene nucleus in the molecule and having an acryloyl group equivalent of not more than 1000, together with or without at least one other compound copolymerizable therewith, under the action of ionizing radiant rays in a molecular oxygen-containing gas to obtain a cured product from said oligoacrylate.

Abstract: A low viscous and solvent-free curable composition comprising a polyester type oligo(meth)acrylate having a plurality of (meth)acryloyl groups, and a polyol poly(meth)acrylate.